Mix the cumin, coriander and cayenne with some salt and pepper, then set aside. Heat half the oil in a frying pan, then throw in the onion, peppers and half the spice mix. Cook for about 3 mins. Tip the vegetables into a bowl.
Place pan back on the heat with remaining oil, then fry the steak and remaining spice mix together for 4 mins until cooked through. Tip the steak into a separate bowl, garnishing with coriander. Heat the wraps. Bring everything to the table and let everyone help themselves.